(2013·江西，22)Whenever I made mistakes，the teacher pointed them out with ________.

According to a UN report，one third of the world population have no    to clean drinking water and health care.

The most important _____ of his speech at the G20 summit was that we should all unite to fight against the financial．

Scientists are hoping for a _____ in the search for a cure for cancer. 

Tom is into sports.When young ,he had a _____about becoming a famous football player.